Check Valve Cap Structure for Low-Cost Seat Relief Retention

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Solution Overview

Problem

Existing check valve units in tensioners require precise machining and additional components, leading to increased machining and production costs, and are prone to plunger deformation and abrasion during press-fitting.

Innovation Solution

A simplified check valve unit design featuring a metal cap member with radially protruding contact surfaces and a seat relief with reduced outer diameter, allowing for elastic deformation and secure fastening without precise machining, and including features like intermediate raised surfaces and communication grooves for adjustable oil flow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the seat relief is press-fit into the plunger bore and secured to the attachment part, then the check valve unit is securely retained, but precise machining of the outside diameter of the seat relief and inside diameter of the plunger bore is required, increasing machining costs

Engineering Contradiction:

Improveretention reliabilityVSAvoidmachining cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The cap member incorporates a resilient (flexible) skirt that can elastically deform during installation and then recover to provide continuous contact pressure against the attachment part's inner circumferential surface. This flexible element replaces the need for precise press-fit machining by using elastic deformation to achieve secure retention with less stringent dimensional tolerances.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The invention changes the material parameter of the cap member by using a resilient material that can elastically deform. This parameter change allows the cap member to adapt to variations in the attachment part's dimensions, securing the check valve unit reliably without requiring high-precision machining of the seat relief and plunger bore.

Inventive Principle:

Principle #35Parameter changes

2Ease of manufacture

If a resin-made retention member is used to secure the check valve unit, then precise machining of the seat relief and plunger bore is not required, reducing machining costs, but the number of components increases, increasing production costs

Engineering Contradiction:

Improvemachining costVSAvoidnumber of components

Core Design Contradiction:

Ease of manufactureVSDevice complexity

Solution Approach 1:

The invention merges the functions of the cap member and the retention member into a single integrated component. The cap member's resilient skirt directly contacts and secures the check valve unit to the attachment part, eliminating the need for a separate resin-made retention member. This integration reduces the number of components while maintaining the benefit of reduced machining requirements.

Inventive Principle:

Principle #5Merging (Combining)

3Reliability

If the press-fitting process is used to secure the check valve unit, then the check valve unit is retained, but abrasion on the resin retention member may occur, requiring careful press-fitting

Engineering Contradiction:

Improveretention reliabilityVSAvoidabrasion

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The cap member is made of a resilient material that combines the benefits of flexibility and durability. This material can elastically deform during installation to accommodate dimensional variations without suffering from the abrasion issues that plague resin retention members. The resilient material's ability to recover and maintain contact pressure provides reliable retention while being more resistant to wear during the installation process.

Inventive Principle:

Principle #40Composite materials

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This design reduces production costs, prevents plunger deformation, and enhances the resilience and durability of the check valve unit, ensuring reliable retention and adjustable oil flow without the need for precise machining or additional components.

Implementation Method 1

The cap member is made of a resilient material and is elastically deformable. The cap member is inserted into the attachment part with the check valve unit, whereby the cap member is elastically deformed and resilient force is generated, so that the check valve unit is firmly fastened to the attachment part.

Methodology Applied

Scientific EffectElastic deformation: Elasticity

Data Source

PatentUS12196334B2Check valve unit

Publication Date: 2025.01.14 TSUBAKIMOTO CHAIN CO

AI summary

To provide a simple-structured check valve unit that allows for retention of a seat relief in an attachment part of a plunger bore, facilitates production without increasing components, and prevents deformation of the plunger. The check valve unit includes the seat relief and a cap member. The plunger has an outlet relief hole in the attachment part for communication between the inside and outside of the plunger. The cap member includes a cap top, an oil flow portion, and a skirt wall. The skirt wall includes a plurality of outwardly raised contact surfaces and a plurality of inwardly raised contact surfaces. The circumscribed circle of the outwardly raised contact surfaces has a larger radius than the inside radius of the attachment part, and the inscribed circle of the inwardly raised contact surfaces has a smaller radius than the outside radius of an engaging part of the seat relief.